In my previous post I included a Boeing 747 into the synopsis and since I don't have informations about the safety- or labour-costs included into the Soyuz launch costs yet I now consider the Boeing 747 as one of the alternatives t/Space say may be used as air launcher for the CXV.

According to Boeing the price of a Boeing 747 actually is ranging from $ 205 mio to $ 236.5 mio. I was looking for informations about the economical lifetime of such airplanes and found one. But I wasn't satisfied because I missed something and so I didn't download it. I will have to look for better informations. But the one I wasn't content with said that airplanes usually are in service for 10,00 hours of flight - may be it spoke of 20,000 hours.

If the information still to be checked and improved or enriched is applied to depreciate a Boeing 747 per hour of flight then depreciations of $ 20,500 to $ 23,650 per hour at a lifecycle of 10,000 hours and $10,250 to $ 11,825 at alifecycle of 20,000 hours of flight.

This seems to be not that much and could be neglected nearly. Even if the two hours between take-off of the air launcher and touch-down of the launcher are assumed it is not that much. What might be of meaning is the possibility to fly away from bad weather at the spaceport and airlaunch elsewhere.

Additionaly it is a question for me if a new Boeing 747 would be modified or a used one - which seems to be more reasonable to me.

Next I am thinking about what might be done with the tanks - may be the tanks are more voluminous than required for an air launcher because less propellant might be needed.

Ekkehard I dont think you could use the 10,000hr figure to depreciate a 747 over. Most of the stress on an aircrft happens at take off and landing which, hopefully, would be similar to the rate for spacecraft launch. Also 747s are used mainly on long haul flights where they spend quite a few hours (6-8+ ???) cruising at a constant speed and altitude which causes less wear and tear on the airplane. I think a much better number would be the number of individual flights that an aircrft could be expected to undertake.

In addition the stresses would be totally different with a launcher slung under a wing which would effect its lifespan. For these reasons I would have thought that the lifespan would be significantly less, although what I couldn't begin to guess at.

_________________A journey of a thousand miles begins with a single step.

what you say I too had in ind when I was looking for informations. I didn't find the data yet which is one of the reasons why I found the information I got unsatisfying and will look for more, more complete and better ones.

In so far I used the hours only as a kind of backup which I don't want to use as part of what I am doing - at least not stand-alone.

The number of flights I would prefer - regardless of how long they last. In principle I would prefer to speak about the numbers of starts and landings.

The time one single flights lasts is essential regarding the capability to leave a region of bad weather - a capability which causes costs which are linked to revenues because some delays can be avoided which can't prevented using vertical launch from ground.

Hello, Peter,

I will look into your link.

Since I didn't do that yet and also didn't find satisfying informations myself yet I have to avoid to comment the percentages here as well as the total costs.

In between I found an information like that I was looking for. It's only one small information and it is given for a small airplane - an Ilyushin. I got it from Wikipedia.

The information says that the lifetime of that Ilyushin is 20,000 lamdings. There is another number too which isn't landings but I concentrate on the number of landings here.

If that number is applied to the Boeing 747 then the depreciations per landing are between $ 10,250 and $ 11,825.

But I am wondering a bit if the number can be applied to the Boeing 747 and there is your doubt, Andy Hill, if the usual lifetime can be kept if the CXV is carried. For this reason I am doing another calculation and then a consideration now.

If the number of landings is dropped to 5,000 then the depreciation per landing would be increased to between $ 41,000 and $ 47,300 only - the propellant costs of the CXV are nearly twice that costs and the propellant costs of the Soyuz might be five times that costs. At 1,000 landings the propellant costs of the Soyuz would be equalled.

The consideartion has to be done from another direction because of this - the question for when the depreciation per landing equals the costs of the hardware of the first stage of a n Soyuz rocket.

I take simply the possible $ 30 to 35 mio used in a recent post. The propellant for one complete Soyuz launch is between $ 200,000 and $ 250,000 if I remember correct my earlier calculations. So I suppose to be close to the correct hardware costs by using between $ 29.5 mio and 34.5 mio for all the Soyuz-stages together. According to the informations I am using here - I don't have available the german link currently - a Soyuz U2 is 54.1 m long and weighs 23.1 tons. The first stage has a length of 19.6 m which is 36.2 % of total - it weighs 14.2 tons which is 61.47 % of total. The Soyuz has six engines in total of which the first stage has four - 66.67% of total. And I can use the surface. The total surface is 478.65 m^2 to which the first stage contributes 165.02 m^2 - 34.48%. The number based on the engines will be too small I fear because the engines of the first stage I suppose to be more expensive than those of the upper stages. The reason is that They have to lift a larger weight and will need to be more crafty. But currently I don't know how to get a better value and additionaly the engines alone would neglect other costs.

The four percentages applied to the $ 29.5 mio and the $ 34.5 mio result in $ 10,679,000 or $ 12,489,000 for the length, $ 18.133.650 or $ 21,207,150 for the weight, $ 19,666,666 or $ 23,000,000 for the engines and $ 10,171,600 or $ 11,895,600 for the surface. These numbers seem to indicate that the first stage costs between $ 10.5 mio and $ 23 mio. The $ 23 mio is got using the engines but is missing the material and the like which should be added for this reason - on the other hand it might be overestimeting all since it menas that the first stage costs two thirds of the total three-stage rocket. So I consider a value of $ 25 mio to be the upper boundary of the costs of the first stage of a Soyuz rocket here. The lower boundary is $ 10.5 mio.

The Boeing as first stage is competitive to this as long as the depreciation per alnding is kept equal or below the valid number between these two boundaries. A Boeing 747 used to airlaunch the CXV needs to be capable of between 20 and 23 landings if the costs of the Syouz rocket are equal to the lower boundary but 9 or ten landings only if the costs of that first stage are equal to the upper boundary.

I personally think that a Boeing 747 carrying a CXV to do an air launch as a lifetime of much more than 23 landings - the lifetime will be several hundred landings at least I suppose. At 100 landings the depreciations per landing are $ 2.5 mio to 2.36 mio and at 1,000 landings they are at $ 205,000 to $ 236,000 only.

Consequently I suppose the first stage of a CXV not to contribute that much to the launch costs as far as hardware is considered - regardless if these depreciations are included into the launch costs of $ 20 mio already or if they still have to be added to them.

Up to now I used an all new Boeing 747 and it has been doubted if 20,000 landings can be assumed if this all new Boeing 747 woiuld carry a CXV.

But I suppose that not an all new Boeing 747 would be used but a secodn-hand one. In that case the number of 20,000 flights could be applied - the major portion of them would have occurred in normal use of the Boeing while some a left which are available for carrying the CXV until the lifteime of the Boeing 747 is over.

I could apply any number of lfights left here but I chosse two special ones. The first is 2,000 flights which would mean that 905 of the lifetime is over and the Boeing 747 is depreciated down to $ 23,650,000. Then the depreciation could be $ 11,825 per CXV-service..

The second number is the number of flights according to a remainder of $ 25 mio left from the price of $ 236 mio - which is slightly more than the first number. The Boeing would have been depreciated down to 10.57% of its initial price then - resulting in an according number of flights of 2,114. The depreciations then are the same as for the first number.

A lot of CXV-launches could be done via the Boeing 747 obviously without being a significant share of the CXV flight-costs.

Rgearding the price of the Boeing 747 the question comes up to me if the airplane is involved into the $ 400 mio-investment into the CXV. $ 236.5 mio for the Boeing 747 would be too much. So if the airplane is included into the $ 400 mio then it will be the depreicted Boeing.

Perhaps an airpalne of $ 25 mio is involved. I will look at it in the next psot.

Before going on I should add a source I used in recent post - I took some informations I missed at wikipedia from www.bernd-leitenberger.de

Talking about a $ 25 mio-airplane in the previous post I am using the number I get if I suppose that of the $ 150 mio reported as the investment costs of Virgin Galactic's vehicles $ 50 mio are the costs of the two WK2s which would mean that one WK2 costs $ 25 mio. The article Soyuz linked too and I have quoted in the previos post explicitly says that the WK2 has been increased to be able to do orbital operations. In the Accumulations-thread I already linked to another article quoting Virgin Galactic's president Whitehorn to have said that they have in mind to do orbital operations.

This doesn't mean yet that they have increased the White Knight so that it could launch a CXV. But the article Soyuz found says that the WK2 originally - when the total investment into the vehicles still has been said to be $ 135 mio. - had the size and wingspan of a Boeing 737 whie it is now increased to the size and wingspan of a Boeing 757. Looking at the homepage of the Virgin Group I recognized alink to Virgin Express and had a look there. Virgin Express is using several Boing 737s. Theiur prices are listed as $ 34 mio and $ 37 mio while the original WK2 seemed to cost $ 17.5 mio each ($ 35 mio in total added to the $ 100 mio for the five SS2s). If that's the cost of one WK2 really than the difference to the Boeing 737 will include a margin refletcing the name and image of Boeing at least. This is not justified by material or production. Next there will be amargin which is due to Boeing's market power. This margin also has nothing to do with material and production. There is remainder caused by the
material and productions costs to create the volume required for passenegrs or freight (it seems to be freight in the case of Virgin Express). So this comparison might indicate the payload capacity the WK2 would have had originally -I couldn't find the weight of the SSO but there is an information at Scaled Composite's homepage that the WK(1) had a payload capacity of 8,000 lb which is slightly less than the weight of a CXV.

I had a look at Virgin Atlantic's homepage too but didn't find any airplane prices. But they too are familiar with Boeing's airplanes since they use Boeing 747s...

Since the WK2 will hjave the size and wingspan of a Boeing 747 I had a look at Boeing's homepage too. A Boeing 737 costs between $ 45.5 mio and $ 77 mio - which might mean that the prices have been increased since Virgin Express bought their airplanes. But it might mean alternatively that Virgin Express managed to get rebates or/and reduced prices - due to marekt power or Branson's financial weight perhaps. If I want to find out the payload capacity of the WK2 by the prices I will get a smaller payload capacity by using the prices listed by Boeing. Unfortunatle I couldn't find prices of the Boeing 757 since it isn't produced nomore. So I looked for the prices of Boeing 767s which are ranging from $ 112 mio to $ 153 mio. Using all these numbers I calculate that a Boeing 737 is between 2.6 times and 4.4 times as expensive as the original WK2. Dividing the Ã¼rices of the Boeing 767 by these numbers I get between $ 44 mio and $ 34 mio - this is above the $ 25 mio for the increased WK2 but may be due to not using a Boeing 757 but the Boeing 767. Additionally the costs for the material and production of volume for freight and/or passengers is included.

Turning to the payload capacity I found that a Boeing 737-700C can carry 18,200 kg and has a wingspan of 34.3 m. Compared to that a Boeing 757-200 Freighter can carry a payload of 39,780 kg at a wingspan of 38.05 m. Ass I listed in the synopsis in an earlier post the CXV and its booster together might weight 21,592 kg - without the propellant. This would be much too much for the Boeing 737 but is within the capacity of a Boeing 757. But the WK2 will have a weight advantage over the Boeing 757 beacuse the WK2 doesn't need material and construction for passenger capacity or freight-capacity. So there is a chance that the increase of the WK2 enables it to carry and launche the combination of the CXV with its booster. A problme seems to be the propellant the weight of whonos calculated to be 376,420 kg in total. But this togther with the hardware-weight would even not fit into the maximum takeoff weight of a Boeing 747-400 Freighter.

The fact that t/Space is speaking of the possibilty to use a modified Boeing 747 to launch the CXV and the reuslt above that the total weight of propellant, CXV and booster wouldn't fit into the maximum take-off weight of the Boeing 747 is ahint that the amount of propellant and perhaps the weight of the booster is calculated too hight here. This would be due to the circumstance thjat at least the calculation of the weight and the cylindrical volume of the booster is weak up to now.

Next t/Space says that the landing gear of the Boeing 747 would be modified. This I suppose to be meant to get space for the CXV and its booster - but it might be that such a modification also increases the maximum take-off weight. The VLA will be constructed from beginning so that the required space and maximum take-off weight is available. All this means that the costs structure of the CXV with its booster is better than calculated in this thread up to now.

If the increased WK2 really can launch the CXV and costs $ 25 miio each then it would be a new airplane but not a second hand Boeing 747 and so may have a lifetime of significantly more than 2,000 flights dropping the depreciation per CXV-launch fdown from $ 12,500.

Informations about the weight of the SS2 and the payload capacity of the WK2 will be very very interesting for this thread.

I will go on to try to analyse this possibilty - in the next post I will do the special consideration of the VLA/increased WK2.

First now the special consideration of the WK2 for the case it can carry the CXV including its booster and the propellant of the booster.

The WK2 is developed, constructed and built to launch the suborbital SS2 initially and orbital operations are an additonal purpose. So it has been considered in the Accumulation-thread - applying flight number of between 500 and 3000 for two WK2s in total (five SS2s in total). These are between 250 and 1500 flights per WK2. But these numbers are applied for a five-year-period only. Five years is only the time from beginning of suborbital operations and breaking even. Since Virgin Galactic's intention is to get profits at least twice the number of flights per WK2 can be supposed - between 500 and 3000 flights. And it might be even more.

So if one White Knight 2 costs an investment of $ 25 mio each WK2 would be depreciated at between $ 50,000 and $ 8,333 - and it would be even less if one White Knight 2 can do more than 3,000 flights. Up to now it looks as if these depreciations would be got by the suborbital operations and business - for launching a CXV less or now depreciations could be applied.

Now initially the two WK2s seem to have cost an investment of $ 35 mio only - $ 17.5 mio each. If only these are deprecciated via the suborbital business then the orbital operations would have to depreciate $ 7.5 mio per Wk2 only. If depreciations of $ 50,000 would be done per orbital flight then $ 7.5 mio/$ 50,000 = 150 flights. At depreciations of $ 10,000 there would have to be 750 orbital launches while at $ 100,000 75 orbital flights would be sufficient.

Obviously if the WK2 can launch the CXV the depreciations to done in or for the orbital business are going to be marginilzed reagrding the airplane. This already is a kind of economies of scope.

In between I tried to find out more regarding the question of the weight of the CXV-booster-propellant-combination under the aspect that it can be launched by a Boeing 747.

First there is the weight and amount of propellant. As far as I remember I didn't apply the Ziolkovsky-formular but simply calculated the maximum amount of propellant fitting into the cylindrical volume of the booster. But the number wasn't correct because I missed data about some properties of cerosene and LOX such as density and so whonos psoted a correction and the calculation he got it by. Since this is a maximum amount it seems to be likely that this amount is too much.

Throughout this thread I tried to apply too hight numbers where low numbers would be in favour of the CXV or something else and too low numbers where high numbers would be in favour. The fact that the sum of the weights of the CXV, its booster and the propellant is higher than the maximum takeoff-weight of a Boeing 747 which according to t/Space could launch the CXV logically means that the weight calculated and the amount of propellant calculated is too high. The maximum takeoff-weight of the Boeing 747 is an upper boundary of that weight.

Obviously CXV + booster + propellant can't be heavier than 396,900 kg - and so not 398,112 kg which I get as sum currently. And t/Space doesn't speak of removing the non-required hardware of the Boeing 747.

The maximum optional payload capacity listed by Boeing is 123,970 kg while the maximum payload capacity non-optional is 112,630 kg. The difference of these to the maximum take-of-weight seems to be the sum of the weight of engines, material the airplane is made of and fuel - 272,930 kg to 284,270 kg. The share of the proeppalnt is the weight of maximum 57,285 U.S. gal (216,840 L). I didn't look yet for that weight.

The weights valid for the Boeing 757 I don't apply any longer since only the size and wigspan of that airplane have been used to describe the increased WK2 and the weight of the engines and material is unknown currently.

Because there seems to be a ready QuickReach in fall as I understand Air Launch LLC there may be interesting additional number available then. Also I suppose numbers about the WK2 to oublished this year perhaps.

In the next post I will have a look to variable costs and do an enhanced synopsis perhaps.

To complete the calculations regarding the airplane and/or the first stage of the Soyuz I had considered the propellant costs. According to Boeing the maximum fuel capacity of a Boeing 747-400 freighter is 57,285 U.S. gal (216,840 L). The 216840 seem to be liters which I used to get the costs for that amount. According to Wikipedia the density of cerosene is between 0.747 and 0.84 g/cm^3. Then I get a weight of between 161,979.48 and 182,145.6 kg. At the 0.65 $/kg used earlier these cost between $ 105,286.66 and 118,394.64. If I assume that such an amount is required for the maximum flight distance of 8,230 km only and reduce it to 100 km or 1000 km I get costs of between $ 1,279.30 and 1,438.57 or 12,793.03 and 14,385.74. The data regarding the first Soyuz-stage I got from www.bernd-leitenberger.de again. The first stage consumes 157,080 kg of propellant. The ratio between oxygen and cerosene is 2.56. This I understand so that oxygen plus cerosene is 3.56: 2.56 oxygen + 1 cerosene. Using this I get
112,956.49 kg oxygen and 44,123.60 kg cerosene. The costs then are $ 11,295.65 for oxygen and 28,680.34 for cerosene - 39,975.98 in total. Obviously the propellant-costs of the first stage of the Soyuz are significantly higher than the propellant-costs of the Boeing - even if it would fly 1,000 km to launch the CXV. Of course I didn't account for the fuel required for take-off here and applied proportionality where there will be over-proportionality but the correction wouldn't increase the costs to twice or three times the number calculated.

So there seems to be an advantage of propellant costs of the Boeing 747 compared to the Soyuz-first-stage. This advantage may be even higher in the case of the VLA.

Looking into the .pdf you listed, Peter, I get no significant additional costs using the data since most of them have to do with service not being done when the Boeing is used for the air launch of the CXV. The data about the fuel the .pdf is using alos won't be valid since the Boeing will not be going large distances to do the launch.

Since I have the weight of the propellant of the Boeing now I can have a closer look to the boundaries. The maximum take-off-weight is 396,900 kg. If the fuel capacity of 216,840 L would be used fully then this amount weighs between 161,979.48 kg and 182,145.6 kg leaving 264,920.52 kg and 214.854.4 kg. But since the Boeing will not have to go the maximum distance the amounts for 100 km and 1000 km should be used here - between 1,968.16 kg and 2,213.20 kg or between 19,681.59 kg and 22,131.99 kg. These would leave between 394,931.84 kg and 393,686.80 kg or between 376,218.41 and 374,768.01 kg. These numbers include the optional maximum payload capacity of 123,970 kg. Then for material, engines etc. plus the saved propellant-weight would be left between 270,061.84 kg and 269,716.80 kg or between 252,248.41 kg and 250,798.01 kg. After subtraction of the saved propellant weight of between 160.011.24 kg and 179,932.40 kg or between 142,297.89 kg and 160,013.61 kg the weight of the Boeing without propellant and
payload seems to be between 142,297.89 kg and 89,784.40 kg or between 109,950.52 kg and 90,784.40 kg. These weights can't be removed completely since the VLA or WK2 need to have engines, wings, tanks, a pilot cabin and all what's needed to dock the suborbital SS2 or any CXV-booster-propellant-combinations - but these high numbers of kgs won't be removed from the Boeing 747 I think - t/Space only are speaking about modifications of the landing gear.

For he CXV-booster-propellant-combination then only weights of between - optional maximum payload plus saved propellant-weight - 283,981.24 kg and 303,902.40 kg or between 266,267.89 kg and 283,983.61 kg are left.

Because of all the above it would be interesting to replace the upper boundary by a value closer to the reality now.

Looking to the synopsis posted earlier in this thread I listed a wrong weight of the airplane. Since I can enhance the synopsis now I do the correction also.

- CXV vehicle-weight requiring less propellant
- CXV first stage has less propellant costs
- CXV first stage has less hardware-costs per flight
- CXV first stage is fixed costs which don't grwo by number of flights
- CXV vehicle-length and -radius resulting in less surface and thus material
- CXV booster-length and -radius resulting in less surface and thus material
- reusability of CXV first stage and thus flight rate (> 1)
- CXV first stage-take off by combination of horizontal take-off with speed causing buoyancy which saves propellant to get thrust
- reusability of CXV vehicle and thus flight rate (>1)
- reusability of CXV-launching airplane and thus flight rate (>10 to 23 flights)

The cost advantage results in savings above a flight rate of seven flights regarding the CXV and ten to 23 flights regarding the airplane.

I am still searching and looking for the labour- and safety- costs of a Soyuz-launch. There was an article reporting the number of NASA-employees. I am thinking about using that number but don't consider it to be a good base yet because the russian equivalent may differ significantly.

I calculated much earlier a radius of 2.1 m for the CXV-QuickReach â€“ which is the diameter of the first QuickReach obviously â€“ so this means that the diameter will be doubled.

Next I used a length of 27.2 m â€“ which is longer by 7.4 meters only.

And I got a weight of 39,503.2 kg â€“ by 6,844.54936 kg too much: The QuickReach itself seems to be ging to be lighter than I concluded.

This might mean that also the amount of propellant the CXV-QuickReach will need is less than calculated. I already wonder if they used a QuickReach for their tests that isnâ€™t as heavy as the QuickReach at launch will be. ...

Looking a bit closer and more precisely on it all I recognized that I applied a QuickReach 1-radius of only 0.5 meters. I have to check if that was the informations avilable but I think so. Then the radius of the initial Quickreach will have been increased by a factor of more than 4. May be that's an adjustment. But in particular it may compensate the length - I will do the calculation later.

Regarding the weight I looked at the wrong row in an Excel-spreadsheet I am using - I calculated that weight for the QuickReach 2. So that weight might be far too low if the QuickReach tested isn't a QuickReach 2. I can't imagine that but the radius is catchin my thoughts.

But the weight might be no problem any longer if the QuickReach 2 is double-staged also - or vene have more stages. The staging I will include into calculations also.

I didn't find the time to redo some calculations yet but I am thinking a bit about the way to handle the staging from time to time - that's limited because of another study of mine.

The point I am interested in at present is that a portion of the 72,000 pounds of QuickReach1 will be dropped. This I suppose to occur at QuickReach2 also. This will be more in favour of a launch via the Boeing 737-spanned WK2 than a single stage QuickReach2 weighing those 72,000 pounds.

In principle I have an approach to handle the staging but no numbers about the emty weight(s) are available. So there has to be work about that which partly seems to be assisted by the thoughts in the other study.

It seems to be required to evaluate the graphics about the two-staged QuickReach1.

It's just a pity that I don't find the opportunity to go on considering this also.

Using a ruler it seems that the propellant is stored over a length of 60% to 70.555...% of the entire QuickReach2 - all two stages together.

41.666...% seems to be the tank for the LOX and the propane of the first stage together while 18.333...% to 28.888...% seem to be the tank for the second stage.

The diameter seems to be 11.111...% of the total length and is - as usual for rockets - constant along the tanks. So it might be that it is sufficient to apply the length(s) only for the purposes here because the required amounts of materials for the empty QucikReach grow proprtional to the length if the diameter doesn't change along the tanks.

The data are very raw data but will be of help - they can be applied to the absolute data known. To do so will enable to conclude to the costs weight and the costs - propellant costs and investment into the stage(s) - of the QuickReach2. I am thinking about averages but may be that something like that is not required. At present it seems to be more interesting to me to apply a largely simplified version of the method pllied in the Lunar Soyuz-thread.

Of course the tank walls and one nozzle must be subtracted from the volume of the propane tank of the first stage. But that will be not that much I think.

Under www.bernd-leitenberger.de I read that tank-walls are very thin in between and Micro Space's lander also has tank walls as thin as less than a millimeter (I will check that again).

But there is the connection between then nozzel of the second satge and the tanks of that stage. It is 4.444...% as long as the whole QuickReach and the diameter is 25% of the diameter of the whole QuickReach.

Because of the shape of the tanks this will tend to overapproximate the propellant costs - but it may overapproximate the weight and the required amount of materials of the empty QuickReach also. This means a safety margin.